In modern avionics systems (for example, in Integrated Modular Avionics (IMA) systems), partitioning operating systems are typically used to meet stringent safety- and mission-critical requirements. Aeronautical Radio Inc. (ARINC) has promulgated the “ARINC Specification 653: Avionics Application Standard Software Interface” family of specifications (generally referred to here as “ARINC 653”). The family of ARINC 653 specifications includes a “Draft 3 of Supplement 1 to ARINC Specification 653: Avionics Application Standard Software Interface,” published Jul. 15, 2003 (also referred to here as “ARINC 653-1”).
ARINC 653 defines an APplication EXecutive (APEX) for space and time partitioning for enabling multiple partitions to share a single processor and memory in order to guarantee that applications executing within one partition cannot adversely affect other partitions in the event of an application failure. Each partition in such an ARINC 653 system represents a separate application and makes use of memory space that is dedicated to it. Similarly, the APEX allots a dedicated time slice to each partition, thus creating time partitioning. Each ARINC 653 partition also supports multitasking within it.
ARINC 653 was defined assuming the use of a single core processor. However, the processor industry has transitioned to multi-core processors for various reasons. As a result, most high-end processors are multi-core processors.
However, the cores of a multi-core processor often share hardware resources and can significantly interfere with each other's performance. This interference can violate the guarantee of robust partitioning (a guarantee that partitions do not interfere with each other) that is fundamental to ARINC 653 and IMA systems. As a result, when such multi-core processors are used to implement ARINC 653 systems, all but one of the cores in the multi-core processors are typically disabled. This is a significantly inefficient use of hardware, and the inefficiency worsens as the number of cores per processor increases.